Hardware Design of Data Acquisition and Processing Module of Fiber Grating Demodulator

Abstract

A data acquisition and processing module of fiber Grating demodulation instrument based on FPGA (Field Programmable Gate Array) + Dual-port RAM (Random Access Memory) + ARM (Advanced RISC Machine) is designed. Due to the fast sampling rate of FPGA, arm has obvious advantages in floating-point operation and host computer data exchange. Therefore, the design can take into account the data processing and transmission rate while ensuring the fast data sampling rate, and can significantly improve the operation speed and stability of demodulation equipment. The hardware circuit of the module is optimized to reduce the noise of the hardware circuit and improve the stability of data processing results. The half-peak detection algorithm is used to locate the center of fiber Bragg grating reflected spectral signal, which improves the data processing speed. The conic curve fitting method is adopted to improve the measurement accuracy. The central wavelength drift of the data acquisition and processing module is $$\pm 3$$ pm, and the demodulation rate is 30Hz. This paper provides a design idea of data acquisition and processing module, which has reference significance to the design of radar signal processing board and optical fiber sensing hardware circuit.